78353891 has 32 divisors (see below), whose sum is σ = 105024000. Its totient is φ = 57788640.

The previous prime is 78353857. The next prime is 78353897. The reversal of 78353891 is 19835387.

It is a happy number.

It is not a de Polignac number, because 78353891 - 2¹⁴ = 78337507 is a prime.

It is a super-2 number, since 2×78353891² = 12278664469679762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78353897) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 71141 + ... + 72233.

It is an arithmetic number, because the mean of its divisors is an integer number (3282000).

Almost surely, 2^78353891 is an apocalyptic number.

78353891 is a deficient number, since it is larger than the sum of its proper divisors (26670109).

78353891 is a wasteful number, since it uses less digits than its factorization.

78353891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1144 (or 1130 counting only the distinct ones).

The product of its digits is 181440, while the sum is 44.

The square root of 78353891 is about 8851.7733251592. The cubic root of 78353891 is about 427.9110709202.

The spelling of 78353891 in words is "seventy-eight million, three hundred fifty-three thousand, eight hundred ninety-one".